开发者

How to split a string with multiple delimiters in vba excel?

开发者 https://www.devze.com 2023-04-11 01:54 出处:网络
I want to split a string with multiple delimiters using Excel VBA.One of the strings is: d1-d2 d3 d4 We have a dash and a space as two delimiters. I tried the split function but it only do开发者_如

I want to split a string with multiple delimiters using Excel VBA. One of the strings is:

d1-d2 d3 d4  

We have a dash and a space as two delimiters. I tried the split function but it only do开发者_如何学Pythones it with one delimiter.


You could first do a Replace on the string first and then do the split:

newString = Replace(origString, "-", " ")
newArray = Split(newString, " ")


To split with several different delimiters ; list the delimiters in an array, replace them with a for loop, then split :

' New delimiter
tDelimNew = "myDelimiter"

' Replace each possible delimiter
For Each tDelimOld In Array(";", " ", ".", "<==", ":", vbCr)
    tString = Replace(tString, tDelimOld, tDelimNew)
Next tDelimOld

' Remove duplicate delimiters
tString = Replace(tString, tDelimNew & tDelimNew, tDelimNew)

' Split ;)
tResult = Split(tString , tDelimNew)


The previous answer is good, but will cause you to have trouble if there are back to back characters to be split on that are in the String, such as splitting "Hello, Sir! How are you doing, today?" on all punctuation and spaces. In this case, you would get a blank string between Hello and Sir.

To handle this scenario Chip Pearson provides a great VBA function for use: http://www.cpearson.com/excel/splitondelimiters.aspx


Not allowed to comment (yet) but suggestion of using TRIM to eliminate a double space is not fully clear. The TRIM function in VBA only deletes leading and trailing spaces. It does not touch double spaces inside a string. You would have to use the worksheet function for that.


I'll add that I had a quick look at Chip Pearson's answer, and thought it could be improved a little in terms of performance, so I wrote my own which appears to be about 40% faster (feel free to test yourself). It's faster (1.0E-5 vs 1.7E-5 seconds per cycle) because it uses byte arrays rather than actual characters to compare values. Here's the function which returns a string array like Chip Pearson's:

Function SplitMultiDelims2(Text As String, DelimChars As String) As String()
    '''
    'Function to split a string at multiple charachters
    'Use like SplitMultiDelims2("This:is-a,test string", ":-,")
    'Returns an array, in that example SplitMultiDelims2("This:is-a,test string", ":-,")(4) would be "test string"
    '''
    Dim bytes() As Byte
    Dim delims() As Byte
    Dim i As Long, aub As Long, ub As Long
    Dim stack As String
    Dim t() As String
    Dim tLen As Long
    tLen = Len(Text)
    If tLen = 0 Then
        Exit Function
    End If
    ReDim t(1 To tLen)                           'oversize array to avoid Redim Preserve too often
    bytes = StrConv(Text, vbFromUnicode)
    delims = StrConv(DelimChars, vbFromUnicode)
    ub = UBound(bytes)
    For i = 0 To ub
        If Contains(delims, bytes(i)) Then
            aub = aub + 1
            t(aub) = stack
            stack = ""
        Else
            stack = stack & Chr(bytes(i))
        End If
    Next i
    t(aub + 1) = stack
    ReDim Preserve t(1 To aub + 1)               'Works marginally faster if you delete this line,
    'however it returns an oversized array (which is a problem if you use UBOUND of the result,
    'but fine if you are just looking up an indexed value like the 5th string)
    SplitMultiDelims2 = t
End Function

'and a 2nd function called by the first one
Function Contains(arr, v As Byte) As Boolean     'checks if Byte v is contained in Byte array arr
    Dim rv As Boolean, lb As Long, ub As Long, i As Long
    lb = LBound(arr)
    ub = UBound(arr)
    For i = lb To ub
        If arr(i) = v Then
            rv = True
            Exit For
        End If
    Next i
    Contains = rv
End Function

Here's the test log (his is SplitMultiDelims, mine is SplitMultiDelims2)

> SplitMultiDelims: 1.76105267188204E-05s per cycle 'this is the important figure
> i = 568064 iterations in 10.00390625 seconds
>Test completed: 08/06/2017 10:23:22
> SplitMultiDelims2: 1.05756701906142E-05s per cycle
>i = 947044 iterations in 10.015625 seconds
>Test completed: 08/06/2017 10:23:32
> SplitMultiDelims2: 1.04176859354441E-05s per cycle
>i = 960656 iterations in 10.0078125 seconds
>Test completed: 08/06/2017 10:23:54
> SplitMultiDelims: 1.76228941673255E-05s per cycle
>i = 567887 iterations in 10.0078125 seconds
>Test completed: 08/06/2017 10:24:04

Run in both directions to avoid memory writing handicaps

Test code below uses Timer so not overly precise, but good enough to demonstrate the difference

Sub testSplit()
    Dim t As Double, dt As Double
    Dim s As String
    Dim i As Long
    t = Timer: i = 0: dt = 0: s = ""
    Do Until dt > 10                             'loop for 10 seconds
        s = SplitMultiDelims("This:is-a,test string", ":-,")(1)
        dt = Timer - t
        i = i + 1
    Loop
    Debug.Print "SplitMultiDelims: " & dt / i & "s per cycle" & vbCrLf & "i = " & i; " iterations in " & dt; " seconds" & vbCrLf & "Test completed: " & Now
    t = Timer: i = 0: dt = 0: s = ""
    Do Until dt > 10                             'loop for 10 seconds
        s = SplitMultiDelims2("This:is-a,test string", ":-,")(1)
        dt = Timer - t
        i = i + 1
    Loop
    Debug.Print "SplitMultiDelims2: " & dt / i & "s per cycle" & vbCrLf & "i = " & i; " iterations in " & dt; " seconds" & vbCrLf & "Test completed: " & Now
End Sub


in which case you could do

    newString = Replace(origString, "-", " ")
    newString2 = replace(newstring, "  " , " ")
    newArray = SPlit(newString, " ")
0

精彩评论

暂无评论...
验证码 换一张
取 消

关注公众号